A carbonator known in the art is configured to be retrofitted to existing bottled-water dispensers to compliment the normal cold water dispensing operation thereof with the dispensing of carbonated water. (see, for example, Pereira U.S. Pat. No. 4,597,509). One disadvantage encountered with carbonators of this type is that such configurations are not conducive to low-cost manufacture of a dedicated dispenser. In addition, a carbonator of such configuration operates with the limitations of the primary or host apparatus.
Another deficiency in carbonators of this type is the lack of an adequate control system to disable the carbonating pump when no carbonating water is present. Further, the type of pump used cannot run dry without being damaged and without overheating. Since consumers often do not change water containers until the receiving reservoir is completely dry, pump protection is important.
Most drinking water coolers hold and dispense cooled water at about 40-50.degree. F. Dispensing carbonated water at the higher end of this range results in rapid decarbonation that is detectable by the consumer. If such carbonated water is further diluted with flavoring syrup, the resulting drink is `flat` by most standards. Since most drinking water dispensers are not engineered to build significant amounts of ice, only a limited number of carbonated drinks of high quality can be drawn from such a modified dispenser.
In the home environment, carbonators may be configured to stand alone, for example, as countertop units which must be refilled from available tap water or, alternately from pressurized water mains. Units of this type must be protected from operating unnecessarily with concomitant reduced lifetime and against damaging operation associated with depletion of a refillable water reservoir. Also, such water reservoir should be conveniently removable for periodic cleaning and refilling to avoid the growth and accumulation of mold and fungus. Another difficulty encountered with carbonators for home applications is the waiting time associated with carbonating the water to make a soft drink. Further, the current market demands more convenience and quicker availability of a finished soft-drink than is commonly possible with known carbonators (See, for example, Child et al, U.S. Pat. No. 4,401,607, Child et al, U.S. Pat. No. 4,422,371, Adolfsson, U.S. Pat. No. 4,509,569, and Jeans U.S. Pat. No. 4,564,483). Systems of these types, although simple and of low cost, are generally of the batch-type, require a number of manual operations and are unable to produce substantially on-line supplies of carbonated water. Also, although high-quality and convenience syrup post-mixing systems are available for home use, such systems are costly and beyond the means of most consumers. Since these systems are commonly downscaled commercial systems, their size and complexity of operation require a degree of learning and skill most consumers will not tolerate.
Concerns by a growing number of consumers about contaminants in potable water supplies have created much interest in bottled and purified water for beverages. As a result, beverage systems which can use only municipal sources may have a perceived disadvantage for consumers who do not have water purification equipment already installed. Systems which use municipal water as the supply source are usually adaptations of commercial post-mix systems of which examples are cited above.
Carbonated beverage dispensing systems have also been described for home use by incorporating the system into the home refrigerator (See, for example, Sedam et al U.S. Pat. No. 4,306,667 and Re 32, 179, and Shikles, Jr. et al U.S. Pat. No. 2,894,377). Systems of these types have been directed toward the storage and dispensing of flavoring syrups concurrently with the dispensing of carbonated water. The equipment and complexity added by the syrup-mixing equipment typically increase the costs beyond reach of most consumers.
Another difficulty encountered with prior-art systems of the type described above is that they are not well adapted for use in small offices or in the home. In one such soft drink system as described by Gaunt et al U.S. Pat. No. 4,635,824, the system appears to minimize the costs and amount of syrup-mixing equipment required, but appears to be directed primarily at brix control (sugar content and flavor strength) and less at the carbonator and the other elements of the system. While some attention is given the accuracy of post-mix flavor mixing systems in the prior art, it appears that consumer tastes vary with respect to the preferred soft-drink flavor strength. Some of the prior-art systems provide for varying flavoring strength in post mix systems (See, for example, Donahue U.S. Pat. No. 3,756,473), but such systems commonly include associated storage and dispensing equipment which increase size and cost. In the past, carbonated soft drinks were made by placing a small amount of flavoring concentrate in the bottom of a beverage glass, adding carbonated water, and stirring with a spoon. While this procedure worked well in commercial soda fountain environments, it is not well suited to use in the home or office where use of a spoon is inconvenient. It does, however provide a means for easily varying the strength of the beverage to individual taste.
Other beverage dispensing apparatus are also disclosed in the literature (See, for example, U.S. Pat. Nos. 2,823,833; 3,292,822; 2,735,665, 2,588,677, 3,225,965, 3,726,102, 4,304,736, 2,894,377, Re. 32,179, 4,440,318, 4,093,681, 4,225,537, 4,635,824, 4,632,275, 4,655, 124, 4,597,509, 4,564,483, 4,518,541, 4,509,569, 4,475,448, 4,466,342, 4,422,371, 4,401,607, 4,316,409, 4,242,061, 4,222,825, 4,205,599, 4,173,178, 4,068,010, 3,761,066, 3,756,576, 3,756,473, 3,926,102, 3,495,803, 3,408,053, 3,397,870, 3,292,822, 3,225,965, 2,823,833, 2,798,135, 2,735,370, 2,560,526, 1.872,462, 1,115,980, 780,714.